Object-oriented methodology

• Class
  • base - derived/subclass
• Object
  • is an instance of a class
  • three properties characterize objects
    • identity
    • state (members)
    • behaviour (methods)
• Inheritance - a.k.a generalization
• Subtyping - adding details to a generic datatype to create a more specific datatype
• Members
  • public
  • protected
  • private
• Methods
  • Instance Method - is associated with an object
  • Class Method - is associated with a class, a.k.a. static method
  • Constructor (instantiation)
    • Instantiates a Class
    • Establishes Class invariant
  • Copy Constructor
  • Deep/Shallow Copy
  • Destructor
  • Accessor
  • Mutator
  • Abstract Method - has no implementation
• Virtual Function - is a function that when overridden by a subclass will be used by the base class
• Polymorphism - ad-hoc (overloading), parametric (templates?)
  • polymorphic function - can evaluate to and be applied to values of different types
  • polymorphic datatype - contains elements of different datatypes
• UML Diagrams
  • Class Diagrams
    • Generalization
    • Aggregation, Composition
  • Object Diagrams
  • Sequence Diagrams
  • Collaboration Diagrams
  • StateCharts
• The Liskov Substitution Principle - Functions that use pointers or references to base classes must be able to to use objects of derived classes without knowing it
• Implementations
  • C++
  • Java
  • JavaScript
  • Python
  • Ada
  • SmallTalk
  • Eiffel
  • ...